L·ACTU

Hiding your location data from Uber is possible thanks to a cryptographic protocol developed by researchers at HEC Lausanne and EPFL

How can you hide your private location data when you use Uber? Researchers at the Faculty of Business and Economics (HEC Lausanne) and EPFL have developed a cryptographic protocol which puts a rider and potential drivers in contact while keeping their data private from the service provider (for example, Uber). Called ORide, the prototype enables users to organize a journey with only the driver and the rider knowing the origin, destination and route. It will be presented in the summer at two technical conferences specialized in security and privacy overseas across the Atlantic. It is up to companies such as Uber to decide whether they are interested, since the researchers have made a voluntary decision not to file an application for a patent.

From Uber’s lack of data protection...

Kévin Huguenin, Assistant Professor in Information Systems at HEC Lausanne and Jean-Pierre Hubaux, Professor in the School of Computer and Communications Sciences at EPFL, quickly realized that data protection was something that had attracted little attention compared with the reluctance Uber has faced in Europe. The recent scandals involving the US company that have recently broken out and been covered by the global media have proved them right. From security breaches to passenger data being freely available to employees and geolocating users after their journey: in the era of Big Data, there has been no shortage of criticisms levelled at these various aspects of Uber’s business.

The challenge was therefore to see whether it was technically possible to preserve the key participants’ private data without affecting the performance, functionalities or usability of Uber’s ride-sharing service. “This research is part of a broader project on protecting location data, particularly location traces,” explains Prof. Huguenin. “The example of Uber-style ride-hailing struck us as particularly important, given its popularity and risks for users’ privacy. The fact that data can be exchanged between different participants (riders and drivers), rather than just between riders and the service provider, raised some particularly interesting problems.”

The result was ORide (“O” for “oblivious”), a prototype based on a cryptographic system based on somewhat homomorphic encryption, which makes it possible to perform computations on encrypted data without seeing either the data or the result.

... to the development of a unique prototype

How does the cryptographic system work in practice? When a rider is looking for a ride, they send their location data to the drivers available via the service provider. The drivers calculate the distance between them and the passenger and send it to them in an encrypted form. The passenger can therefore identify the driver closest to them. ORide then pairs the two users’ smartphones and shares their location data. The route taken is only stored in the rider’s and driver’s smartphones. Ultimately, the service provider only knows the distance covered and price of the journey – so the company can charge its fees for the journey and the rider can provide proof of their expenses. In addition, ORide retains the usability of the original app, including credit card payments and the ability to rate the driver.

In order to evaluate their protocol, the scientists used public data from taxi drivers in New York City. The city has a population equivalent to the whole of Switzerland and roughly the same number of taxicabs as vehicles managed by Uber and its competitor Lyft. According to their analysis, the calculation does not have any significant impact on how quickly a passenger can find a driver.

There is now one important final step for the researchers: ORide will be presented at the prestigious USENIX Security conference (one of the so-called big-four security conference) in August, in Vancouver (BC) in Canada.